Table Of ContentSTUDIES IN VISUAL INFORMATION PROCESSING 3
Series Editors:
Rudolf Groner
Institute for Psychology
University of Bern
Switzerland
Géry d'Ydewalle
Department of Psychology
University of Leuven
Belgium
NORTH-HOLLAND
AMSTERDAM · LONDON · NEW YORK · TOKYO
FACETS OF DYSLEXIA
AND ITS REMEDIATION
Edited by
Sarah F. WRIGHT
Rudolf GRONER
Insitute for Psychology
University of Bern
Switzerland
1993
NORTH-HOLLAND
AMSTERDAM · LONDON · NEW YORK · TOKYO
NORTH-HOLLAND
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ν
PREFACE
This volume represents the edited proceeedings of the 18th Rodin Remediation
Conference on Reading and Reading Disorders. The conference had as its main theme
the impact of fundamental research on new ways of understanding reading disorders,
with an emphasis on both the role of basic visual processes in reading and dyslexia, and
on developmental issues and methods of early diagnosis. The Conference was held at the
University of Bern Children's Hospital, Switzerland, between August 27 and 29th,
1991, preceded by a day of presentations in German. The participants of the main
conference were invited to submit a chapter to this book. A selection of those were edited
and are included in this volume. A special issue of the Schweizerische Zeitschrift für
Psychologie, 1992, Vol. 51,1, contains papers from the first day.
The conference was organised by Ruth Kaufmann-Hayoz and the editors. It was
generously supported by both the Rodin Remediation Academy and the Max and Elsa
Beer-Brawand Foundation. The Rodin Academy, based in Kerns in Switzerland, aims at
"redressing the adverse personal and social consequences, both congenital and
conditioned by development, which retard or impair the learning processes, which in turn
are connected with reading, writing and speaking". Composed of researchers and
scholars from many scientific fields, one of the Rodin Academy's central activities is the
support and organisation of international conferences.
The Max and Elsa Beer-Brawand Foundation supports special events at the University
of Bern of cultural and social importance which are beyond the funding capacity of the
university. These include meetings and symposia which should be of general interest and
open to the public. Additional support was also provided by the Swiss Academy of
Humanities and Social Sciences.
The editors would like to express their heartfelt thanks to Ruth Kaufmann-Hayoz for
her many ideas and help. Thanks are also due to Björg Jakob and Ruth Parham for their
much welcomed assistance and support, both before and during the conference. We
would also like to extend our thanks to the members of the programme committee who
helped in the selection of papers: the late Günther Baumgartner, Curt von Euler, François
Gaillard, Dieter Heller, Giorgio Innocenti and Per Uddén. Finally we would like to thank
all those who attended the conference and all who submitted papers.
vi
CONTRIBUTORS
Janette Atkinson, Visual Development Unit, University of Cambridge, 22
Trumpington St., Cambridge CB2 1QA, UK
Monica Bisealdi, Neurology Clinic, University of Freiburg, Hansastr. 9, D-7800
Freiburg, Germany
Bruno Breitmeyer, Department of Psychology, University of Houston, Houston TX
77004-5341, USA
Marc Brysbaert, Laboratory of Experimental Psychology, Catholic University
Leuven, Tiensestr. 103, B-3000 Leuven, Belgium
Salome Burri, Psychology Department, University of Bern, Gesellschaftsstr. 49, CH-
3012, Bern, Switzerland
Panajotis Cakirpaloglu, Institute of Physiology, Videnska, 1083, CSFR-Prague 4,
Czechoslovakia
Evelyne Corcos, Glendon College, University of York, Psychology Department, 2275
Bayview Avenue, Toronto, Ontario M4N 3M6, Canada
Piers Cornelissen, Physiology Department, University of Oxford, Parks Road,
Oxford ΟΧΙ 3PT, UK
Neville Drasdo, University of Aston, Birmingham B4 7ET, UK
Guinevere Eden, Physiology Department, University of Oxford, Parks Road, Oxford
ΟΧΙ 3PT, UK
Janice Edwards, Dyslexia Institute, 133 Gresham Rd., Staines TW18 2AJ, UK
Bruce Evans, Institute of Optometry, 56-62 Newington Causeway, London SEI 6DS,
UK
Angela Fawcett, Department of Psychology, University of Sheffield, PO Box 603,
Sheffield S10 2TN, UK
Heather Fields, Academic Psychiatry Department, Middlesex Hospital, Mortimer St.,
London WIN 8AA, UK
Burkhart Fischer, Neurology Clinic, University of Freiburg, Hansastr. 9, D-7800
Freiburg, Germany
François Gaillard, University of Lausanne, BFSH 2, CH-1015 Lausanne,
Switzerland
Gad Geiger, Department of Biomedical Engineering, Rutgers University, Piscataway
08855, New Jersey, USA
Evi Graf, Swiss Cerebral Palsy Association, Loretostr., 35, CH-4504 Solothurn,
Switzerland
Jane Greene, Basics Plus Education Centers, 4100 General DeGaulle 4, New Orleans
LA 70131, USA
vii
Rudolf Groner, Psychology Department, University of Bern, Laupenstr. 4, CH-3008
Bern, Switzerland
Rolf Hänni, Psychology Department, University of Bern, Gesellschaftsstr. 49, CH-
3012 Bern, Switzerland
Robyn Hill, Anxiety Disorders Unit, St Vincent's Hospital, 299 Forbes St.,
Darlinghurst 2010, Australia
Karl-Ludwig Holtz, Pädagogische Hochschule Heidelberg, Keplerstrasse, 87, D-
6900 Heidelberg, Germany
Morag Hunter-Carsch, School of Education, University of Leicester, 21 University
Rd., Leicester LEI 7RF, UK
Ruth Kaufmann-Hayoz, Interfakultäre Koordination stelle für Allgemeine Oekologie,
Niesenweg, 6, CH-3012 Bern, Switzerland
John Kershner, Ontario Institute for Studies in Education, 252 Bloor St. West,
Toronto, Ontario M5S 1V6, Canada
Richard Kruk, Department of Psychology, University of Wollongong, Wollongong,
NSW 2500, Australia
Katie LeCluyse, Department of Psychology, University of New Orleans, LA 70148,
USA
Jerome Lettvin, Department of Biomedical Engineering, Rutgers University,
Piscataway, New Jersey, USA
William Lovegrove, Department of Psychology, University of Wollongong,
Wollongong, NSW 2500, Australia
Catherine Meyers, Laboratory of Experimental Psychology, University of Leuven,
Tiensestr. 103, B-3000, Leuven, Belgium
David Moseley, School of Education, University of Newcastle-upon-Tyne, Ridley
Building, Claremont Place, Newcastle-upon-Tyne NE1 7RU, UK
Peter Müller, Psychology Department, University of Bern, Laupenstr. 4, CH-3008
Bern, Switzerland
Stanton Newman, Academic Psychiatry Department, Middlesex Hospital, Mortimer
St., London WIN 8AA, UK
Roderick Nicolson, Department of Psychology, University of Sheffield, Sheffield
S10 2TN, UK
Naoyuki Osaka, Department of Psychology, Kyoto University, Kyoto 606, Japan
David Pestalozzi, Ophthalmologist, Solothurnerstr. 19, CH-4600 Olten, Switzerland
Susan Pickering, Department of Psychology, University of Sheffield, Sheffield S10
2TN, UK
Tomas Radii, Institute of Physiology, Videnska, 1083, CSFR-Prague 4,
Czechoslovakia
viii
Ian Richards, University of Aston, Birmingham B4 7ET, UK
Alex Richardson, Physiology Department, University of Oxford, Parks Road, Oxford
ΟΧΙ 3PT, UK
Christiane Rieth, Max-Planck Institute for Brain Research, Deutschordenstr. 46, D-
6000 Frankfurt, Germany
Anita Rock-Faucheux, Department of Psychology, University of New Orleans, New
Orleans, LA 70148, USA
Doris Safra, Ophthalmologist, Myrtenstr. 3, CH-9010 St Gallen, Switzerland
Dieter Schoepf, Neurology Clinic, University of Hamburg, Martinistrasse, 52, D-
2000 Hamburg, Germany
Wolf Singer, Max-Planck Institute for Brain Research, Deutschordenstr. 46, D-6000
Frankfurt, Germany
Ruxandra Sireteanu, Max-Planck Institute for Brain Research, Deutschordenstr. 46,
D-6000 Frankfurt, Germany
Ronald Stringer, Ontario Institute for Studies in Education, 252 Bloor St. West,
Toronto, Ontario M5S 1V6, Canada
John Stein, Physiology Department, University of Oxford, Parks Road, Oxford, OX1
3PT, UK
Fuchuan Sun, Shanghai Institute of Physiology, 320 Yo-yang Rd., 200031 Shanghai,
China
Ulrike Tymister, Albert-Ludwigs University of Freiburg, D-7800 Freiburg, Germany
Aryan van der Leij, Department of Special Education, Vrije Universiteit, Van der
Boechorststr. 1, NL-1081 BT Amsterdam, The Netherlands
Jean Whyte, Clinical Speech and Language Studies, Trinity College, Dublin 2, Ireland
Mary Williams, Department of Psychology, University of New Orleans, New
Orleans, LA 70148, USA
Dale Willows, Ontario Institute for Studies in Education, 252 Bloor St. West,
Toronto, Ontario M5S 1V6, Canada
Frank Wood, Bowman Gray School of Medicine, Winston Salem, North Carolina,
USA
Sarah Wright, The Barn, Drayton-St-Leonard, Oxford, OX9 8BQ, UK
Regina Yap, Department of Special Education, Vrije Universiteit, Van der
Boechorststr. 1, NL-1081 BT Amsterdam, The Netherlands
Wolfgang Zangemeister, Neurology Clinic, University of Hamburg, Martinistrasse
52, D-2000 Hamburg, Germany
xiv
INTRODUCTION
Developmental Dyslexia has been a subject of interest to practitioners for more than a
century (e.g. Berlin, 1872; Morgan, 1896; Hinshelwood, 1900). Dyslexia represents a
severe and persistence difficulty with the written form of language and affects a
substantial proportion of children nationwide. Despite its long research history, dyslexia
still provides a challenge for contempory cognitive psychology, education, neurology and
physiology. By bringing together contributions from authors working in a wide range of
fields and perspectives, it was hoped that the current book would offer a means of
considering different facets of dyslexia and enable a greater understanding of reading
disorders and their remediation to emerge.
The book is divided into eight major sections. The focus in each section, is on a
different facet of dyslexia. Inevitably, given the diversity of the contributions, and the fact
that many chapters cover more than one facet, the division is not always optimal.
However, the intention was to provide a framework which would enable the reader to
assimilate the wide range of pure and applied research, a framework which may even give
rise to a new perspective for the understanding of dyslexia. Although the majority of the
chapters use - as does the title of the book - the term 'dyslexia', the terms 'specific
reading disability', 'reading disability' and 'learning disabled' are also used
interchangeably.
In the first chapter, Sireteanu, Singer & Rieth investigate the development of texture
segregation in infants and children. They find that while babies at the age of two months
can be shown to have a preference for a figure defined by differences in blob size, it is
not until the end of the first year that preference is shown for a figure differing from the
background by the orientation of its elements. This preference becomes adult-like at an
age when children begin to acquire reading and writing skills. Given this finding, an
interesting hypothesis might be put forward for a relationship between learning to read
and the maturation of cortical mechanisms necessary for the segmentation of figures in a
cluttered visual environment.
Sustained and transient channels play an important part in the visual scanning of an
extensive display, including textual material. In the second chapter, Breitmeyer argues
that from theory and empirical evidence a visual deficit in reading disability based on
weak transient channel functioning is likely. The inhibition which transient channels exert
on sustained channels is important for the efficient pick-up of pattern information in
fixation-saccade sequences and for maintaining constancy and visual stability. A deficit in
the transient system would result in less efficient pick-up of pattern information during
reading as well as leading to attendant problems with motion smear and visuospatial
instabilities.
XV
The discussion of a possible transient system deficit in dyslexies is further explored by
Lovegrove. Interestingly, sustained system functioning, which is primarily concerned
with extracting information from stationary stimuli, has not been found to differ between
dyslexies and non-dyslexics. Addressing the confusion in the literature, Lovegrove
argues that one reason some studies have failed to show differences between dyslexies
and controls in visual processing may be due to the fact that they have measured sustained
system processing while those which did find a difference have measured transient
system functioning.
Dyslexies, it seems can foveally identify isolated letters presented tachistoscopically
against a blank background, performing as well as non-dyslexic readers. However, when
short letter strings or words are presented, dyslexies do considerably worse than non-
dyslexics. Geiger & Lettvin investigate this phenonemon further by briefly exposing pairs
of letters on a screen with one letter presented at the centre of gaze and the other in the
peripheral field along the horizontal axis. In successive presentations the peripheral letters
are presented at different eccentricities. The response to each pair is recorded and the plot
of the average of correct peripheral letter identification with varying eccentricity
determined. Differences in the resulting shapes of these plots between dyslexies and non-
dyslexics are attributed to lateral masking. Dyslexies perceive the letters best in the near
periphery in the direction of reading but at the same time they perceive a large portion of
surrounding text since it is poorly masked.
Studies using computer presentation have found that dyslexies read better when text is
presented one word at a time, whereas normal readers perform better when text is
presented a whole line at a time. Hill & Lovegrove examine the relationship between one
word advantage and transient activity. They suggest that since the transient system is
involved with processing the textual information surrounding the fixated word, removing
peripheral information (i.e. presenting one word at a time) should result in improved
reading in dyslexies who have a transient deficit. The results confirm this suggestion that
dyslexies with a weak transient system do read better when potentially disruptive context
is removed.
Rock-Faucheux, LeCluyse and Williams expand on Lovegrove's work by studying
the perceptual consequences of a transient deficit in disabled readers. Investigating the
effect of colour on reading, Williams and co-workers find that blue overlays produce
significant improvement in the reading comprehension of disabled and normal readers,
while grey overlays produce an improvement for the dyslexies alone. The effect of using
blue and grey overlays on reading performance in reading disabled subjects is attributed
to the creation of a better temporal separation between transient and sustained responses,
which may compensate for the visual deficit of disabled readers.
xvi
Corcos and Willows examine the role of visual processing in good and dyslexic
readers' utilization of orthographic information in letter strings. The results of their
multiple regression analysis shed important light on the types of cognitive processing
factors that contribute to the variance in the processing of orthographic information. Their
results suggest that Grade 2 and 4 students display an increasing reliance on visual
processes when they processed pseudowords, a reliance which decreased in Grade 6
when speed of retrieval becomes more important.
Previous studies on the optimal viewing position effect have shown that the processing
time of isolated words depends on the letter initially fixated. Shortest latencies are found
when subjects are fixating between the first and the middle letter. Brysbaert & Meyers in
the next chapter, compare the response patterns of normal adults, children with reading
disability and their matched controls. They found a more pronounced optimal viewing
position effect in both samples of children compared to adults. Manipulation of the
children's initial fixation location seemed to have a larger effect than manipulation of the
adults' initial fixation location, despite the fact that the children's naming latencies were
much longer. However, considerable interindividual differences between children can be
found.
Atkinson highlights the similarities between sight reading music and reading text and
investigates to what extent the same problems encountered by dyslexies in reading text
might be found in sight reading music. In one experiment, the children are required to
sight read music both by singing and by playing their instruments. A significant
difference is found between dyslexies and controls - with a number of the dyslexic
children unable to sight read at all despite nine months musical tuition.
In the next chapter, Cornelissen poses the question 'Do children's visual problems
affect how they read?'. He finds that children with unstable fixation, i.e. those who have
failed the Dunlop Test, read differently when print size or viewing conditions are
changed, but that the same changes have no effect on children with normal vision. The
demands made on children's language processing skills were 'clamped' at a fixed level
when they read. Therefore, because the change in children's reading errors is brought
about by changing only the visual component of the reading task, these experiments
suggest a direct link between the efficiency of visual processing and reading and lead to
the conclusion that unstable binocular fixation does indeed affect how children read.
Although there is growing evidence that disabled and normal readers do differ in
performance on tasks designed to assess visual processing, the extent to which various
perceptual, cognitive and linguistic processes may contribute to that performance has
seldom been directly assessed. Willows, Corcos and Kershner use factor analysis and
multiple regression to relate performance on a large battery of tests assessing visual,
phonological, linguistic and memory processes to performance on tasks assessing
